The present invention relates to a cylinder head gasket for an internal combustion engine. More particularly, the invention relates to cylinder head gasket having a self-energizing combustion seal flange.
Gaskets 10 are often used to provide a seal between an engine block 12 and a cylinder head 14 of an internal combustion engine. As shown in FIGS. 1-3, known cylinder head gaskets 10 typically include a flange 16 that extends around the periphery 18 of cylinder bores formed in the gasket 10 to provide a combustion seal for maintaining the high temperature gases of combustion within the cylinder bores. A typical combustion flange 16 has a generally semicircular cross-sectional shape with the outmost portion 20 of the flange 16 extending away from the periphery 18 and into the combustion bore.
Referring to FIGS. 1 and 2, during operation of the engine, combustion explosion forces (represented by arrows A) act upon the flange 16. As can be seen in FIG. 3, the combustion forces AC try to pass between the overlap of the flange 16 and the cylinder head 14 and heel of the flange 16 and the engine block 12. The tangential forces AT acting on the flange 16 pushes ends 22 of the flange 16 downward and way from the engine block 12 and cylinder head 14, thereby reducing sealing and promoting combustion leaks between the flange 16 and the hardware 12 and 14. Accordingly, more durable combustion seals are required to reduce the opportunity for combustion leaks and increase flange life.
The present invention provides a gasket having a core and a self-energizing seal flange. The core includes at least one gasket plate, wherein the plate has at least first apertures for mating with cylinder bores of an engine block.
In accordance with the invention, the self-energizing seal flange has a generally convex center face that directly addresses a flame front of a combustion bore opening in an otherwise generally concave combustion flange cross-sectional profile. Such a design produces a generally flatter medial profile or face to address the flame front of the combustion zone, thereby minimizing deleterious tangential forces that operate to create gasket leaks and to shorten the life of the flange.